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Arduino Blinking Bike Patch 



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Arduino Blinking Bike Patch 

Written By: Becky Stern 



TOOLS: 


PARTS: 


Arduino IDE software (1) 


Li Power board (1) 


Computer (1) 


Batterv (1) 


Needlenose pliers (1) 


Buy with charaer from Sparkfun or use 


Scissors (1) 


the LilvPadAAA batterv holder if vou 
wish 


Sewing needle (1) 


Conductive thread (1) 




Conductive velcro (1) 




Velcrotape (1) 




Bag(1) 




or backpack 




Fabric (Small scrap) 




for switch 




• Thread (1) 




Li Iv Pad Pro Kit (1) 



SUMMARY 

Here I'll show you how to add flashing LEDs to your backpack for fun and safety. I used a 
LilyPad Arduino with a rechargeable lithium-polymer battery for flatness and re-usability. The 
LEDs blink in a marquee pattern, two at a time, in patriotic red, white and blue. This project 
also appears as a CRAFT Video ! Grab the Source code and schematic 

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Arduino Blinking Bike Patch 



Step 1 — Arduino Blinking Bike Patch 




• Coil the leads of each LED: make the longer lead (positive) into a square spiral, and the 
shorter lead (negative) into a round spiral. 

Step 2 — Sew the LED grounds 




• Check out the schematic. Using your conductive thread, sew a line around the perimeter of 
the patch, stopping to sew the round leads of each LED into the line. Leave a space on one 
edge for the conductive velcro (don't sew the velcro yet). 



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Arduino Blinking Bike Patch 



Step 3 — Sew the power supply and LilyPad 




• Cut one side of the conductive velcro in half, and sew the bottom half over the edge of the 
patch where you left that space earlier. Sew it down and sew a line over to the + on the 
LiPower unit (you can also use the LilyPad AAA battery board). The picture shows it sewn 
to ground, but don't pay attention to that (or better yet, upload a correct image)! 

• Sew the other conductive velcro tab down next to (but not touching) the previously-sewn 
tab. Stitch a line to the + on the LilyPad Arduino. I reinforced these two power leads a few 
times to reduce the resistance of this switchable area. 

• Stitch the ground of the power supply to the line of grounds around the edge. Same goes 
for the LilyPad Arduino. Look at that schematic for help placing the traces. 



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Arduino Blinking Bike Patch 



Step 4 — Sew the LilyPad pins to the LED positive leads 




• This part can take some time. 
According to the schematic, sew 
the positive (square-coiled) leads 
of the LEDs to their respective pins 
on the LilyPad Arduino. Be sure not 
to cross any threads, and tie tight 
knots with close-trimmed ends to 
prevent fraying fibers from shorting 
your circuit. I stopped often to let 
the needle dangle and untwist the 
thread as I worked, as it likes to 
get tangled and caught. 

• At this point you can plug the 
battery into the Li Power and turn 
the thing on. Use the other piece of 
conductive velcro to bridge the two 
patch tabs and see if your LilyPad 
boots up. Press the reset button a 
few times and watch that little 
green LED on board blink a little. 
Now you know it's working! 



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Arduino Blinking Bike Patch 



Step 5 — Program the board 




» Here's the Arduino code! Load it on 
your LilyPad by hooking up your 
programmer and USB cable (or 
FTDI cable if you have a newer 
LilyPad). For more info about 
getting the code onto the Lilypad, 
check out this page at the Arduino 
website: 
http://web.media.mit.edU/~leah/LilyPad/Q.. 



Step 6 — Affix with Velcro 




• I decided to affix the entire circuit patch with velcro instead of sewing it down to my bag, 
with air travel in mind specifically. It's easy to remove, inspect, and replace. I live in 
Arizona, so rain isn't too much of a concern, but it should also be removed during rain. You 
can choose to just remove the battery, as the rest of the circuit won't be damaged by 
water, so long as you wait for it to be completely dry before plugging the battery back in. 

• Sticky-back velcro is easier, but any kind will do! 



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Arduino Blinking Bike Patch 



Step 7 




• Now go ride your bike! 



This document was last generated on 2012-10-31 10:22:21 AM. 



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